Method

First make the aioli. Place the garlic in a bowl with the egg yolks, lemon juice and mustard. Mix both oils in a jug and, whisking constantly, pour them slowly into the egg yolk mixture in a very thin stream. Continue to add the oil, whisking all the time until it has been fully incorporated and the aioli is thick. Season with salt and pepper to taste and set aside.

Slice the rolls in half and toast them on each side, then spread with butter and a little of the aioli. Assemble the lamb, cucumber, red onion, feta and salad leaves on top of one half of each roll, then sandwich together with the other half. Cut the filled rolls in half and serve.